There are some much lighter elements you can use. curium-247 would be ideal.
A long half life (so you can store it), the radiation is all alpha particles, which are undetectable remotely, and is safe to handle (no shielding necessary, just cover it). (However the decay products are much more dangerous, so it's not a total panacea, fresh curium would be desired.)
It has a critical mass of about 7Kg, so it's easy to carry.
Of course the hard part is making it.....
You also have to refine it carefully, since all the contaminants are very radioactive. (However mixing other isotopes of curium with it is not a serious problem, so refining it is not incredibly hard.)
Comments
There are some much lighter elements you can use. curium-247 would be ideal.
A long half life (so you can store it), the radiation is all alpha particles, which are undetectable remotely, and is safe to handle (no shielding necessary, just cover it). (However the decay products are much more dangerous, so it's not a total panacea, fresh curium would be desired.)
It has a critical mass of about 7Kg, so it's easy to carry.
Of course the hard part is making it.....
You also have to refine it carefully, since all the contaminants are very radioactive. (However mixing other isotopes of curium with it is not a serious problem, so refining it is not incredibly hard.)